Here's a caveat before you read the Keirsey NF descriptions. I'm of the view that, while the four MBTI dimensions are largely independent of each other, if you focus on some of the specific personality traits that they can affect, there are various ways for the influence of one MBTI preference to either reinforce or, on the other hand, mitigate/balance the influence of another. You may have heard it said that ENFPs are the "most introverted" of the extraverts — implying that there are aspects of either N or F or P (or some combination of them) that to some extent cuts against E, causing an ENFP to be (or at least seem) less "extraverted" (in one or more specific respects) than other E's. I think, at least with respect to Keirsey's take on NFs, that it may be fair to say that NFPs are somewhat more NF than NFJs — and, in particular, I'm inclined to note that, at least in some respects, I think INFJs are the least NF of the NFs. Although INFJs and ENFPs are in the same group (in terms of Keirsey's 4 temperaments), my take is that a typical INFJ (the "least NF of the NFs," by reckful's reckoning) is at least as close (if not closer) to a typical INTJ as a typical INFJ is to a typical ENFP.
So am I saying that a typical INFJ isn't likely to identify with Keirsey's NF descriptions, or be just as likely to identify with Keirsey's NT descriptions? No — but I think an INFJ is more likely to read some of Keirsey's NF descriptions (and reckful's as well) and feel like they fit pretty well but maybe feel exaggerated or otherwise a bit off of dead center.
In my NT/NF intro, I noted that it was arguably harder to briefly describe what a quintessential INF was like than a quintessential INT and so, in rounding up Keirsey quotes, I was somewhat amused by the abstruseness of this description: "We encounter a special difficulty in attempting to put into words the nature of the [NF]. Where the [other types] pursue ordinary goals, the goal of the [NF] cannot be seen as other than extraordinary. ... The purposes of SPs, SJs, and NTs are understood by SPs, SJs, and NTs alike, although they may not embrace them. ... None of these understand the aim of the NF, and in turn, the NF cannot really grasp the others' commitment to what seems to the NF to be false goals. For the NF pursues a strange end, a self-reflexive end which defies itself: becoming. ¶ While the SPs, SJs, and NTs can go after their goals straightforwardly and at full throttle, the NF's search for self is circular and thus perpetual: How can one achieve a goal when that goal is to have a goal? The NF's 'truest' self is the self in search of itself, or in other words, his purpose in life is to have a purpose in life. Always becoming himself, the NF can never truly be himself, since the very act of reaching for the self immediately puts it out of reach."
Keirsey says: "Although [NFs] make up only about 12 percent of the general population, ... their influence on the minds of the populace is massive, for most writers come from this group. Novelists, dramatists, television writers, playwrights, journalists, poets, and biographers are almost exclusively NFs. Technical and scientific writers tend to be NTs, but writers who wish to inspire and persuade, who produce literature, most often are NFs. ... The theme of people in restless search of self runs through novel after novel, is voiced by protagonist after protagonist, and is the source of agony in drama after drama. ¶ The search for meaning as a necessary pilgrimage for all people is advanced by the NFs in their writings. Very often the other types ... are troubled by the thought that they ought to be pursuing these values, even if, somehow, the search for meaning and integrity does not beckon to them. This reluctance of 88 percent of the world to join the search for self-actualization is a great source of mystification to the NFs."
Keirsey also points out that, "where the SPs are drawn to the performing arts, the NFs are drawn to the arts which involve verbal and written communication," and he notes that, "more than any other group, NFs can speak and write fluently, often with poetic flair."
Keirsey says: "Whether a guru of Esalen or a teacher in a more traditional setting, the profession of transmitting ideas and attitudes tends to attract NFs. Together the SJs and the NFs make up the bulk of public school teaching faculties. Very few SPs or NTs staff the schools of the nation. If the NTs do go into teaching, they gravitate toward higher education. ... SJs outnumber NFs in the teaching field ... roughly three to two. As their subject matter, the NFs tend to choose the humanities and the social sciences."
Keirsey notes that "NFs ... show little interest in buying and selling or any commercial occupations, nor do they find the physical sciences particularly attractive. They prefer to work with words, and need and want to be directly or indirectly in communication with people." And he also notes that money "is one of the least important things to NFs."
Comparing NTs and NFs, Keirsey says: "Although he is apt to be passionate in his pursuit of a creative effort, the NF can be an intellectual butterfly, flitting from idea to idea, a dilettante in his pursuit of knowledge when compared to an NT."
And: "As with the NT, the NF is future-oriented and focused on what might be. But, rather than thinking about the possibilities of principles as does the NT, the NF thinks about the possibilities of people, 'actualizing the potential' of others and of himself. As with his perception of himself, so it is with the NF's perception of others: Whatever is, is never quite sufficient. The thought that the visible is all there is is untenable for an NF." NFs' "hunger is not centered on things but people. They are not content with abstractions; they seek relationships. Their need does not ground in action; it vibrates with interaction."
Similarly, Kroeger and Thuesen state that NFs "eat, sleep, think, breathe, move, and love people."
Kroeger and Thuesen also say NFs "are the idealists of life and they tend to serve causes that advance human interests. ... As idealistic do-gooders, NFs articulate and champion various causes."
Moving to the subject of relationships, Keirsey says: "Both the NF female and male respond to their mates with sympathy, tenderness, and frequent, passionate expressions of love, both verbal and nonverbal. ... NFs are not afraid of using poetry, music, and quotations to enhance their courting relationships; the romantic developments in the lives of NFs thrive on receiving these tokens of affection and dedication. NFs have a flair for dramatizing their courtships, making each the perfect love. A storybook flavor permeates their courtship behavior. ... Seeing their identity as mate is a major part of their personality. ... Just as the possible rather than the actual lures NFs in other parts of their lives, so do the possibilities in relationships inspire them. When a relationship is being established, the recipient of the NF's attention is apt to be the center of his world. The pursuit is given almost single-minded attention and no effort is spared in the wooing. ... Both NF males and females are likely to be blind to any flaws in their beloved in the early stages of a romance."
Keirsey also says: "A danger an NF faces in his intimate relationships is that he will move from relationship to relationship rather than making the necessary effort to develop those already existing. The NF's tendency to experience anticipation as more attractive than consummation can cause him to use his energies pursuing the dream at the expense of what is actually available. Once an NF believes that he or she knows all there is to know about another, disinterest sets in; restlessness and a sense of boredom develop. NFs, as do other types, want a certain amount of variety and change in their lives. Other types, however, may seek this through intellectual pursuits, adjustment of living routines, vacations, new activities. The NF is most vulnerable to seeking this through searching out new relationships, more often than not at the expense of deepening those already existing."
reckful here: I would interject that, to the extent that there's a "fickleness" flavor to the preceding paragraph, I think it's somewhat more likely to apply to an ENF and/or NFP (and especially an ENFP) than an INF or ENJ, but I'd agree that it will tend to be true that, for any NF (as compared to an NT), the relationships in her life are likely to be a focus of her restless energies, with the result that she'll generally tend to want to have some kind of development/change going on in the area of people and relationships — although, with luck, it either won't involve her SO or it will involve her relationship with her SO growing and evolving (—cue roll of male INTJ eyes—) in satisfying ways, rather than the replacement of her SO.
Keirsey says "NF children are apt to enjoy 'people' toys, dolls or animals to which they can attach a personality, and these treasured toys become very much a part of the NF's life. ... The NF child is apt to play with all his toys as fantasy objects, just as does the NT, but the NF is more likely to weave stories around them rather than try to understand them."
Comparing the school interests of Keirsey's four main temperament groups, he notes that the SP student "gravitates toward music, drama, art, crafts, mechanics, construction, or anything active, while SJs tend to enroll in clerical or business classes, the NTs in math and science, and the NFs in the humanities and social sciences."
reckful again: I wouldn't make too much of the NT = sciences and NF = humanities thing. I'm strongly T and I was very good at math/science, but I was always drawn more strongly to the humanities. Keirsey himself is an NT and does psychology (obviously). I'm Limbic, as you know, and it may be that, all other things being equal, a Limbic (more emotional) NT is more likely to be drawn to the humanities than a Calm NT — but I'm just speculating. In any case, I think it's better to think of an NT as a "scholar" (and/or "engineer," used broadly) than as a "scientist," if by scientist you mean the hard sciences.